Substack's new tool tells you who's been writing their newsletters with AI

Substack is rolling out a feature that lets readers see an estimate of how much AI went into writing a newsletter. It's a quiet but significant move in a publishing landscape where the line between human and machine-written content keeps blurring.

The tool doesn't block AI-generated posts or punish writers who use it. Instead, it surfaces the information and lets readers decide what that means to them. That's a pragmatic middle ground in a debate that's mostly been all or nothing.

This matters because trust is the currency of newsletters. Unlike social media feeds or news aggregators, people subscribe to individual writers because they want that person's voice and perspective. When AI enters the equation without disclosure, it changes the implicit deal between writer and reader.

Substack isn't the first platform to grapple with AI content, but they're taking a transparency-first approach rather than an outright ban. That reflects where the industry is heading. AI writing tools aren't going away, so platforms are shifting toward disclosure instead of prohibition.

The bigger question is what readers will do with this information. Will they abandon newsletters with high AI percentages, or will they not care as long as the content is useful? Early signals suggest it depends entirely on the niche and the reader's expectations.

For writers, this creates a new calculation. Using AI for drafts, research summaries, or editing is common and often invisible. But if readers can see a percentage, writers will need to decide how much assistance crosses their audience's comfort line.

What this means for you: if you're publishing any kind of regular content, consider getting ahead of this by being transparent about your process. A simple disclosure about how you use AI tools (research, editing, brainstorming) builds trust before anyone asks. Try this with your AI assistant: "Help me write a brief, honest disclosure about how I use AI in my content creation process. I use it for [describe your actual use]. Make it conversational and reassuring, under 50 words." You can drop it in your about page or author bio.